Dense fibrillar collagen matrices: a model to study myofibroblast behaviour during wound healing.

Fibroblastic cells play an important part in wound healing. Human dermal fibroblasts seeded onto three-dimensional fibrillar collagen matrices migrate into the collagen network and differentiate into myofibroblasts. In order to evaluate the use of collagen matrices as model systems for studying myofibroblast phenotype during wound healing, myofibroblast behaviour migrating into dense or loose matrices was compared.

A cylinder-shaped double ribbon structure formed by an amyloid hairpin peptide derived from the beta-sheet of murine PrP: an X-ray and molecular dynamics simulation study.

A structural model of the murine PrP small beta-sheet was obtained by synthesizing the RGYMLGSADPNGNQVYYRG peptide comprising the two beta-strands 127-133 and 159-164 linked by a four-residue sequence of high turn propensity. The DPNG turn sequence is a "short circuit" replacing the original protein sequence between the two strands. This 19-residue peptide spontaneously forms very long single fibrils as observed by electron microscopy.

Most of the structural elements of the globular domain of murine prion protein form fibrils with predominant beta-sheet structure.

The conversion of the cellular prion protein into the beta-sheet-rich scrapie prion protein is thought to be the key step in the pathogenesis of prion diseases. To gain insight into this structural conversion, we analyzed the intrinsic structural propensity of the amino acid sequence of the murine prion C-terminal domain. For that purpose, this globular domain was dissected into its secondary structural elements and the structural propensity of the protein fragments was determined.

Three-dimensional structure of tubular networks, presumably Golgi in nature, in various yeast strains: a comparative study.

Background: In the yeast Saccharomyces cerevisiae, the Golgi apparatus consists of discrete units distributed throughout the cytoplasm. When such units are examined in three dimensions, in relatively thick sections prepared for the electron microscope, they usually appear as small tubular networks with a stained material accumulating in dilations located at the junctions of membranous tubules. To see whether such tubular networks are observed in other yeast species, the three-dimensional structure of organelles in eight additional yeast strains, endowed with diverse biological properties, are examined.

The operation and efficacy of cryosurgical, nitrous oxide-driven cryoprobe. I. Cryoprobe physical characteristics: their effects on cell cryodestruction.

For specification of the requirements for efficient cell cryodestruction in tumors, we tested a N2O-driven cryoprobe on experimental models. The cryoprobe was a 3-mm-diameter type for operation via fiber optic bronchoscopes in respiratory medicine. The freezing process, namely the "ice-ball" formation around the cryoprobe tip, was monitored with an impedancemeter.